Geological Observations on the Volcanic Islands, visited during the Voyage of H.M.S. Beagle is a book written by the English naturalist based on his travels during the second voyage of HMS Beagle, The text contains seven chapters, and includes observations made during Darwin's travels to the volcanic island of St. Jago in Cape Verde, the Fernando de Noronha archipelago, Ascension Island, the island of Saint Helena, the Galápagos Islands, James Island, New Zealand, Australia, Van Diemen's Land, and the Cape of Good Hope.